Comparison of Predicted Forming Limit Curves with Measured Experimental Data on Hot-Dip Zinc-Coated Cold-Rolled Steel by Incremental Forming Process

2019 ◽  
Vol 821 ◽  
pp. 256-262 ◽  
Author(s):  
Ramil Kesvarakul ◽  
Khompee Limpadapun
Keyword(s):  
Experimental Data ◽  
Incremental Forming ◽  
True Strain ◽  
Single Point ◽  
Forming Limit ◽  
Rolled Sheet ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Cold Rolled ◽  
Forming Limit Curves

Single Point Incremental Forming (SPIF) is a die-less forming process with advantages of high-flexibility, low-cost and short lead time. The high local strains that are applied to the metal sheet, often exceeding the conventional formability limit. This paper is focused on comparison of predicted forming limit curves with measured experimental data on Hot-Dip Zinc-Coated Cold-Rolled sheet, with 0.20 mm thick is studied in single point incremental forming. Truncated square pyramid and cone are formed to study the formability of blank sheets at room temperature. It was found that both Formulation of plastic instability criteria and Keeler’s formula gives the lowest FLC. FLDs have predicted failures in forming process consistently with the real experiments. The experimentally obtained cracking limit differ from analytical one and empirical one by about 3.398 and 2.135 true strain respectively at FLD0, the corresponding plane strain values.

Study on Forming Behaviour of Friction Stir Welded Blanks During Single Point Incremental Forming (SPIF) Process

2020 ◽  
Author(s):  
Shalin Marathe ◽  
Harit Raval
Keyword(s):  
Friction Stir Welding ◽  
Incremental Forming ◽  
Single Point ◽  
Base Material ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process ◽  
Friction Stir ◽  
Welding Processes

Abstract The automobile, transportation and shipbuilding industries are aiming at fuel efficient products. In order to enhance the fuel efficiency, the overall weight of the product should be brought down. This requirement has increased the use of material like aluminium and its alloys. But, it is difficult to weld aluminium using conventional welding processes. This problem can be solved by inventions like friction stir welding (FSW) process. During fabrication of product, FSW joints are subjected to many different processes and forming is one of them. During conventional forming, the formability of the welded blanks is found to be lower than the formability of the parent blank involved in it. One of the major reasons for reduction in formability is the global deformation provided on the blank during forming process. In order to improve the formability of homogeneous blanks, Single Point Incremental Forming (SPIF) is found to be giving excellent results. So, in this work formability of the welded blanks is investigated during the SPIF process. Friction Stir Welding is used to fabricate the welded blanks using AA 6061 T6 as base material. Welded blanks are formed in to truncated cone through SPIF process. CNC milling machine is used as SPIF machine tool to perform the experimental work. In order to avoid direct contact between weld seam and forming tool, a dummy sheet was used between them. As responses forming limit curve (FLC), surface roughness, and thinning are investigated. It was found that use of dummy sheet leads to improve the surface finish of the formed blank. The formability of the blank was found less in comparison to the parent metal involved in it. Uneven distribution of mechanical properties in the welded blanks leads to decrease the formability of the welded blanks.

Experimental Study on Residual Formability of Single Point Incrementally Formed Part

2019 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Single Point ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Conventional Process

Abstract A substantial increase in demand on the sheet metal part usage in aerospace and automotive industries is due to the increase in the sale of these products to ease the transportation. However, due to the increase in fuel prices and further environmental regulation had left no choice but to manufacture more fuel efficient and inexpensive vehicles. These heavy demands force researchers to think outside the box. Many innovative research projects came to replace the conventional sheet metal forming of which single point incremental forming is one of them. SPIF is the emerging die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any processing time to undergo plastic deformation. It has several advantages over the conventional process like high process flexibility, elimination of die, complex shape and better formability. Previous literature provides enormous research on formability of metal during this process, process with various metals and hybrid metals, the influence of various process parameter, but residual formability after this process is untouched. Thus, the aim of this paper is to investigate the residual formability of the formed parts using single point incremental forming and then restrike with a conventional tool. The common process parameters of single point incremental forming were varied, and residual formability was studied through the conventional process. The strain and thickness distribution were measured and analyzed. In addition, the forming limit of the part was plotted and compared.

scholarly journals Simulation of the Single Point Incremental Forming of Polyamide and Polyethylene Sheets

2019 ◽  
Vol 290 ◽  
pp. 03014
Author(s):  
Nicolae Alexandru Roşca ◽  
Mihaela Oleksik
Keyword(s):  
Incremental Forming ◽  
True Strain ◽  
Single Point ◽  
Polymeric Materials ◽  
Single Point Incremental Forming ◽  
Forming Process ◽  
Explicit Analysis ◽  
Polyamide 6.6 ◽  
Experimental Researches

The present paper aims the theoretical study, using the finite element method, on the single point incremental forming process of two polymeric materials: polyamide 6.6 and high-density polyethylene. The experimental researches used for the determination of the true stress - true strain curves for two materials are presented, which are necessary for their introduction into the simulation. The explicit analysis is carried out with the Ls-Dyna program and the results of the analysis were focused on the major strain, minor strain, thickness reduction, forces on the process and total energy consumed in the process.

Revisiting single-point incremental forming and formability/failure diagrams by means of finite elements and experimentation

2009 ◽  
Vol 44 (4) ◽  
pp. 221-234 ◽  
Author(s):  
M B Silva ◽  
M Skjoedt ◽  
N Bay ◽  
P A F Martins
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Incremental Forming ◽  
Single Point ◽  
Analytical Framework ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Forming Limits ◽  
Experimental Values ◽  
Forming Limit Curves

In a previously published work, the current authors presented an analytical framework, built upon the combined utilization of membrane analysis and ductile damage mechanics, that is capable of modelling the fundamentals of single-point incremental forming (SPIF) of metallic sheets. The analytical framework accounts for the influence of major process parameters and their mutual interaction to be studied both qualitatively and quantitatively. It enables the conclusion to be drawn that the probable mode of material failure in SPIF is consistent with stretching, rather than shearing being the governing mode of deformation. The study of the morphology of the cracks combined with the experimentally observed suppression of neck formation enabled the authors to conclude that traditional forming limit curves are inapplicable for describing failure. Instead, fracture forming limit curves should be employed to evaluate the overall formability of the process. The aim of this paper is twofold: (a) to compare the mechanics of deformation of SPIF, namely the distribution of stresses and strains derived from the analytical framework with numerical estimates provided by finite element modelling; and (b) to compare the forming limits determined by the analytical framework with experimental values. It is shown that agreement between analytical, finite element, and experimental results is good, implying that the previously proposed analytical framework can be utilized to explain the mechanics of deformation and the forming limits of SPIF.

New Methodologies for the Determination of Precise Forming Limit Curve in Single Point Incremental Forming Process

2010 ◽  
Vol 97-101 ◽  
pp. 126-129 ◽  
Author(s):  
Ghulam Hussain ◽  
Gao Lin ◽  
Nasir Hayat ◽  
Nameem Ullah Dar ◽  
Asif Iqbal
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Forming Limit ◽  
Single Point Incremental Forming ◽  
Limit Curve ◽  
Forming Process ◽  
Forming Limit Curve ◽  
Groove Test ◽  
New Methodologies

Straight groove test is a widely-used formability test in Single Point Incremental Forming (SPIF). This test does not cover all the forming aspects of SPIF process, however. In order to ascertain its legitimacy, two new tests covering necessary SPIF aspects are devised. The FLC of an aluminum sheet is determined using the newly proposed and straight groove tests. It is found that the straight groove test shows much lower formability than the new tests. Therefore, the employment of newly devised test(s) is proposed for the determination of precise formability limits.

Geometry Compensation Methods for Increasing the Accuracy of the SPIF Process

2021 ◽  
Vol 883 ◽  
pp. 217-224
Author(s):  
Yannick Carette ◽  
Marthe Vanhulst ◽  
Joost R. Duflou
Keyword(s):  
Control Strategy ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Calculation Methods ◽  
Forming Process ◽  
Complex Deformation ◽  
Commercial Use ◽  
Compensation Methods ◽  
Deformation Mechanics

Despite years of supporting research, commercial use of the Single Point Incremental Forming process remains very limited. The promised flexibility and lack of specific tooling is contradicted by its highly complex deformation mechanics, resulting in a process that is easy to implement but where workpiece accuracy is very difficult to control. This paper looks at geometry compensation as a viable control strategy to increase the accuracy of produced workpieces. The input geometry of the process can be compensated using knowledge about the deformations occurring during production. The deviations between the nominal CAD geometry and the actual produced geometry can be calculated in a variety of different ways, thus directly influencing the compensation. Two different alignment methods and three deviation calculation methods are explained in detail. Six combined deviation calculation methods are used to generate compensated inputs, which are experimentally produced and compared to the uncompensated part. All different methods are able to noticeably improve the accuracy, with the production alignment and closest point deviation calculation achieving the best results

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